Air- and gas-borne particulates may comprise a significant environmental hazard. The inhalation of such particulates may exacerbate a number of bronchial and pulmonary conditions such as asthma and chronic obstructive pulmonary diseases. Particulates may be removed from ambient air or gases by a number of different methods. Fabric filters may be useful for filtering particulates having sizes of about 0.5 micron to several hundred microns. HEPA (high efficiency particulate air) filters may be efficient at removing particulates larger than 0.3 microns. Wet scrubbers may be efficient for removing particulates greater than about 0.3 microns, but may lose efficiency when filtering smaller-sized particulates. Electrostatic precipitators may show lowered collection efficiencies for particulates of about 0.1 micron to about 1.0 micron in size.
Many of these systems may be used effectively at the major air intake or exhaust ports of a building such as a factory or home. Fabric or HEPA filters may be commonly used at the air intake side of household furnaces. Wet scrubbers and/or electrostatic precipitators may be used to remove pollutants from exhaust gases at industrial sites. However, these systems may generally be designed to remove particulates from air constantly flowing from one space to another, for example from an open building exterior into the building's enclosed interior. Such systems may not be useful for removing particulates generated in situ, for example cooking smoke within a kitchen. Small electrostatic precipitators may be used to remove particulates from an at least partially enclosed environment, but such units may require frequent maintenance to remove particulates from the ground plate.
Therefore, it is desirable to provide an inexpensive, low maintenance system capable of removing ultra-fine particulates from air especially from within an at least partially enclosed environment.